Fast Calcium Imagings of Amacrine Cell Dendrites in Horizontally Sliced Goldfish Retina

Abstract

Amacrine cells are interneurons that make lateral and vertical connections in the inner plexiform layer of the retina. Amacrine cells have no axon and their dendrites function as both presynaptic and postsynaptic sites. GABAergic amacrine cells constitute 80% of the amacrine cell population in goldfish retina and mediate lateral inhibition between neighboring amacrine cells. Their light-evoked responses consist of regenerative action potentials and excitatory postsynaptic potentials (EPSPs). These depolarizing voltage changes induce Ca²⁺ influx into dendrites, which triggers transmitter release from the storage site in the dendrite. Thus, it is crucial to know how and where Ca²⁺ influx is caused in amacrine cells.